Expansion reamer



Aug'. 14, 1945.-

J. H. GRACEY EXPANSION REAMER Filed Aug. 21, 1943 Jaw-LEE; H- Er c lay I Applicationldugust 2i,

r I J 3 Claims. (01. 77--76) (Granted under the act or March a; 1882, as :Wamended April 30, 1928;370'05G; 757)- v det'ci b fi et i ma h m r fforf the :Governm'entfor Q th i fh p ii nyrQYa-ltythereon." y i I I vention relates to an adjus able expans on reanier. y v c 1 1 11.1154 re lms of a l to r i an B cepti gnally' -smooth iinishf requires [a specially ground rearn'er ch'a'rearner is generally made l ,fllltgd r'eamer/ Each endof v tapered towardthe middle smallecentral portion of the reamer ifghtlyl'lalrgeifdiameter, than the ends. .e,'portiofn oi the .reamer does A am 'p t et i c or'f -thefinal reaming offrifle b u h We 'G iP: 3 010.59 toleranc rnits and to provide a highly "finished face.

an X, are ririjdi ameter than the ends thereof ltj is ore quite apparent that grinding such a tape n exacting procedure. It is also evi faeiittnat w en are emerged center portion of the l he neamer would also be most deo-f this invention 1 is. to provi de a reamen: having readily adfiiistable means flor -expanding such=reamer any 1 desired amount within the elastic l -imitlwofflt-he ream'er steel.

Anothenobject bf-fithis invention is to provide a readily removable shank for a reamer for the purpose of reducing breakage of the reamer and to effect a saving of reamer steel.

Still another object of this invention is to promdu edh ichreamer is h w "TE'Dg STATIE S OFFICE 7 I e 2 ,'ss1,s99 v a a '1 :ev r 'LEXP AlN SION BEAMEIt :fj

James v I L Gracey, Springfield; 1 a

' 1943,.sefiaiisiiiliasaii v vide adequate .oi-l distribution for positive lubrication of .ther'eamer.v I I The .specific nature of the'inve'ntion as well as other objects and advantages-thereof will clearly appear from a description of a preferred erribodimer'it as shown in the accompanying drawinginwhich: v j Fig. 1 is. a side elevational view offthe assembledreaQmerQf f Eig.j2i,is' a right end elevational view ofj'Fig. 1'. Fig. 3 is a longitudinal sectional view 'ofFig, 1. ifis a cross sectional view takenpalonglt he planeffi-lofl 'ig. 3. a x 5 Fig; 5- is a partial longitudinal sectional [view of Fig. lftak'en alongthe plane 3-3 or FigQd' showing the' lubricating' oil passages in the adapter. i V f j a The reamer to'be described in more detail later takes advantage of the elasticity of'thestee1 from which the reamer is fabricated, Briefly the reamer is expanded' by an 'expanderm'ember including a'tapered plug insertable 'in'atapered axial hole within the central portion of the reainer. By advancing. the tapered plug into the tapered hole by ascrew which may or may not be integral with the tapered plug, the'center portion of, the reamer may then be expanded any desiredarnount withinthe elastic limit of the steel, utilized. A threaded adapter is inserted in one end of the reamer in place of the' usu'a integral shank. A' rearner rod is then screwed onto the) otherend of the adapter. 'Awasher placed "between 'thereamer and the adapter breaks upjthefiow of oil coming from the'reamer rod and sprays it evenly" around the flutes {of the rearne'r thereby insuring positive lubrication.

There is shown Figs 1' and'2'in' assembled relation the'expansion' rearner embodying th'is in vention. A straight fluted reamerjl is connected I to a rearner tube {by means'offan adapter 3. Theexterioroi rea ner 'l asshown' in the ac'c'oric panyin figures resembles a conventional cylindricaily ground flutedrearner. Reame l, however, is provided with an axial h-ole' l. The right end of axial hole 4 asviewed in Fig. 3' is counter bored to within a short distance'from'the center of reamer I to provide an enlarged hole '5. A ta pe'red portion 6 is provided from-the bottomof hole'15 to hole 4 which extends a 'short distance beyond the center of ream eel, Theplug' part 7 ofthe expanderwi'll have a't'aper corresponding to that of tapered portion 6 and is for insertion through hole 5 and into tapered portion 6. Counterbored hole 5 is provided with threads 8 to receive the expanding screw portion 9 of the exterior of a reamer tube 2 for the purpose of lubrieating reamer I. the reduced diameter end I2 of adapter 3 and adjacent reamer I. Thus the'washer I6 blocks the oil passages I4 and I5 and forces the oil to be diverted in a manner to be described in" more detail later.

The reamer is readily expanded and adjusted for cutting by turning screw part 9 against tapered plug part I. The pressure brought against part I by the threading of part 9 forces the walls of the reamer to expand outwardly about tapered portion 6 of hole 4. The amount of expansion necessary for a reamer utilized, for example, in finish reaming rifle barrels need be b t two or three ten thousandths of an inch. This amount may be measured by a micrometer or preferably by a ring gage. When the reamer has been expanded at its center section to the required diameter the lock screw I is then screwed into threads 8 to bear tightly against screw 9 thereby locking screw 9 securely in place. The adapter 3 is then screwed into the left end of reamer I as viewed in Figs. 1 and 3 with the washer I6 placed between the two. The end I3 of adapter 3 is then screwed into the threaded end of a conventional reamer tube 2. The lubricating oil passages I4 and I then communicate with the hollow portion I! of reamer tube 2.

The reamer is now assembled to the reamer tube 2 and is ready for finish reaming a bore. When the reamer is inserted in the bore and set in motion the reamerwill out only on the enlarged central portion that has been expanded by the tapered plug I. Lubricating oil is then admitted to the hollow portion I! of reamer tube 2 from a suitable oil source (not shown). The oil should be supplied under pressure so that it is readily forced into the passages I4 and I5 of the adapter 3. Upon striking washer I5 the oil is directed outwardly, spraying out in a fanlike direction thereby positively insuring the lubrication of the cutting edges of the reamer. As the two oil passages I4 and I5 are oppositely disposed to, one another each spray will cover 180 of the circumference of the reamer and will therefore in sure complete and positive lubrication of all the cutting blades.

It is desired to point out that by providing an adapter 3 the usual integral shank generally provided on one end of the reamer may be eliminated thereby effecting a considerable saving in the cost of the reamer. The adapter 3 may be readily made on a screw machine and may be made of less expensive material than the high quality tool steel employed in the fabrication of the reamers. It is readily apparent that if the adapter 3. be made of comparatively soft material such adapter would yield before reamer I in the event the reamer should stick in the barrel A Washer I6 is laced around and thus prevent damage to the reamer. As the adapter 3 is cheaply replaced considerable further saving would thereby be effected.

It is desired to point out that the reamer described herein is preferably used for finish reaming the bore of a firearm barrel but such reamer is not necessarily limited to this application. It is further desired to point out'that the amount of expansion obtainable by such a reamer is limited only by the elastic limit of the material from which the reamer is made. Normally, however, the amount of expansion desired is a relatively small amount so that there is little if any danger of ever exceeding the elastic limit of thereamer material. I

Iclaim:

1. In a tool of the kind described, in combination with a longitudinally-bored body having exterior cutting surfaces, a threaded portion at each end of the bore and an intermediate tapering portion, an expanding member including an externally tapered part at one end and anexternally threaded part at its other end, said threaded part of the expanding member engaging one threaded portion of the bore and said tapered part engaging said tapering portion of the bore, a shank having a threaded portion engaging the other threaded portion of the bore, said shank being provided with a longitudinal lubricant groove therein, and a lubricant dispersion member mounted on said shank adjacent said body.

2. In a tool of the kind described, in combination with a longitudinally-bored body having exterior cutting surfaces, a threaded portion at each end of the bore and an intermediate tapering portion, an expanding member including an externally tapered part at one end and an externally threaded part at its other end, said threaded part of the expanding member engaging one threaded portion of the bore and said tapered part engaging said tapering portion of the bore, a shank having a reduced diameter threaded portion engaging the other threaded portion of the bore, said shank being provided with longitudinal lubricant grooves therein, and a washer mounted on said reduced diameter threaded portion of said shank adjacent said bore,

1 said washer abutting the ends of said lubricant bore, an adapter memberhaving one end portion threadably engaging the other threaded portion of the bore of the body and its other end portion threadably engaging the bore of the reamer tube,

said adapter member being provided with a longitudinal lubricant groove therein, and a lubricant dispersion member mounted on said adapter member closely adjacent said body.

' JAMES H. GRACEY. 

